I presume you are using a database to hold the user IDs and passwords. If
there is only one category of stuff a user can look at, put the category name
in the user's record in the database.

If there are categories of "stuff" the user can access (news, sports, comics,
etc.) and a user can subscribe to multiple categories, you will need a new
table listing all the stuff. Then another table will map users to stuff
categories in a many-to-many relationship. Use a SELECT query with a JOIN to
retrieve all the stuff for a particular user. See sample below.

<!--- user table tblUser --->
id user password
3 harry ihsne56
8 sally cwhr74nd

<!--- mapping table tblMap --->
userId stuffId
3 22
3 43
3 25
8 43
8 56

<!--- stuff table tblStuff--->
id stuff
22 news
25 comics
43 sports
56 weather